Interestingly, the Portuguese NWT edition translates 1 Tim. 6:4 this way:
"ele está enfunado [de orgulho], não entendendo nada, mas tendo mania de criar questões e debates sobre palavras."
A translation into English would be something like this: "he is puffed up [with pride], not understanding anything, but having mania [obsession, delusions, craze] of creating questions and debates about words."
A related term to Portuguese "mania" is "mental illness."
Some English translations used for the Greek word, noson are:
doting, morbid, morbid interest, morbid appetite, morbid fondness, morbid craving, morbid passion, sick, touch'd with a spirit of chicanery and wrangling, delirious, infirm, a sickly longing, an itch, unhealthy concern,unhealthy craving, obsessed, driven mad, etc.
"In classical Greek the noun nosos and the congate verb noseo are used primarily in connection with illness. It can also be used generally of ‘distress, anguish’ and figuratively of character defects and mental illness." (TCBL, Hebrew-English Dictionary)
"Noseo signifies 'to be ill, to be ailing,' whether in body or mind..." (Vine's)
"The use of noseo in 1 Tim. 6:4 corresponds to the Hel. usage of the vb. Craving for controversy and disputes about words point to a sick condition in the inner self." (N.I. Dictionary of NT Theology)